Fluid compressor



Dec. 21 ,1926. 1,611,265

. J. o. cARRl-:Y l 6 FLUID COMPRESSOR j Filed eb. 9. 1920 7 Sheets-Sheet 5 J. o. CARREY` FLUID COMPRESSOR Dec. 21 1926.

y Filed Feb; 9. 1920 7 sheets-sheet 4 v l dal' Dec. .21 1926. v 1,611,265 n v v .'1. o. CARREY I FLUID COMPRESSOR Fiie Feb. 9; 1920l 7 sheets-Sheet 5 J. o. ARREY FLUID COMPRESSOR y Filed Feb. e. 1920 'r sneets4sheet G jizz/e223@ De'c. 21 1926. 1,611,265

. J. O. CARREY l AFLUID COMPRESSOR Filed Feb. 9. 1920 '7 Sheets-Sheet f .Patented Dec. 21,I 192-6.

(UNITED- STATES 1,611,265 PATENT y oFFi'gcs. '3 y JOHN O. CARREY, OF ST. LOUIS, MISSOURI, ASSIGNOR T CARREY-,MOR-SE ENGINEER- ING` COMPANY, OF ST. LOUIS,. MISSOURI, A CORPORATION OFMIS'SOURI.

FLUID comrnn'sson.'

Application led Iiebruary 9, 1920. Serial No'. 357,132.

My invention relates lto a uid compressor, the principal objects of my, invention being to generally improve upon and simgaseous fluids.

plify the construction of the existing and generally used forms of fiuid compressors; and to provide a relatively simple, easrly tween a pair of rotors, one of which is eccentrically disposedwith repect-to the other, is

effective in rapidly compressingto relatiye- I v high degrees of pressure', air and like Further objects of my invention are, to

provide simple and efficient means forv con-l trolling the action of the liquid contained iii 'the chamber between therotors; to` provide means for effectively -controlling the air or other fluids compressed in the machine; to provide simple means which will act automatically when the speed of the compressor is` retarded to seal the housing of the compressor against the escape. of

iuids; to provide improved and effective means for lubricating the' bearings of the compressor; toprovide for the' maintenance of the proper amount of liquid in the chamber between the rotors; and lto provide [simple and effective means fordissemiating any heat which may develop in the operation of the compressor.

Myinvention is characterizedby the vuse of a pair of suitable rotors, one eccentrcally disposed within the other, so asto form an eccentric chamber between the annular wall A of the external rotor and the peripheryv ofthe internal rotor, and to maintain within said chamber a'body of simple'for com" pound liquid which, 'while the' compressor -is in'operation, will by centrifugal forces, be moved outwardly against the annular Wall of the external rotorthereby forming practically an. annular body of liquid which moves with both rotors. 1

The peripheral portion of the eccentriv ,cally disposed internal rotor willf,'in operaltion, move into the annular body-:"fof liquid,

and as said internal rotor is provided in itsv periphery with pockets, any air or like fluids contained therein will be compressed and in suchI condition discharged from the internal rotor and delivered to- .a suitable storage l chamber.

rlhe exibility or density of the annular bodyT of liquid may be varied as desired, or

as conditi-onsmay require. A fixed density 'may be attained ,by a; given speed and varyf` innI tlie radius. or by'maint'aining the same eral speed. may be maintained constant in both cases. J

,radius and varying the speed; or the periphl To attain best results, the two rotoqrs u should bevdriven at approximately the same peripheral speed, and in the same direction. 5

Heretofore,-in the compression of fluids it. has generally been the practice to utilize solid surfaceszwhich approach eachother in effecting theI compression of air or gases;

lView, my invention consists in certain novel features of construction and arrangement of parts, hereinafter more fully. described and claimed, and illustrated in the accompanying drawings, in which l Figure 1 is a vertical section taken my improved construction.

through the center of a fluid compressor of Figure 2 is a vertical section taken approximately on the line 2`2 of Figure. 1.

-Figure 3f is avertical section taken approxim'ately on the line 35,-3 of`Figure 1. Figure 4 is a vertical HIsection .taken approximately on the line 4 4 of Figure 1.

Figure 5 lis a `vertical section/taken approximately on the line 5-5 of Figure l..

Figure 6 is .a longitudinal section of a modified form of my improved compressor. Figure? is a cross section taken approximitely on the line 7-`7 of Figure 6. l f

' igure 8 is an enlarged detail section'illus'- trating a part ofthe journal bearing-oiling system 'utilized 'iii connection with the forni of compressor illustrated in Figures 6 and 7. Figure 9 illustrates a modified form of the dischargevalve.

Figure 10 illustrates form of 'the discharge valve.

a' further modified .Figure 11 illustrates a modified form 'of "l l the overflow valve.

and external rotor's of the compressor and snowing the mobile body that' occupies the chamber between saidrotors and which cooperates with the internal rotor in effecting the compressing action.

. Figure 13 isa sectional'view showing a construction wherein the external rotor is cooled by airA currents .drawn into and through the outer housing of the compressor.

Referring by numerals to the accompanying drawings. which illustrate a practical embodiment of my. invention, designates the. annular wall of the outer housing or shell of the compressor, and formed integraljvith one side of this annular wall is a 'pla-te 11 with the centralfportion of which is formed integral an outwardly projecting tubular bearing 12. The opposite end of the annular wall is closed by a removable plate 13 in the center of which is formed an outwardlyv projectingjtubular bearing 14, the same being in horizontalalignment with bearing 12. Y preferably provided'with suitable bushings 15 and journaled therein is a shaft 16, that? is connected to suitabledriving means,pref erably a motor. yThat portion of the shaft which extends/through the casing or housing formed by the walls 10, 11 and 13 is provided with an axially disposed chamber 17,- its Outer/end being closed by a screw plug 18.

- Formed integral with the plates 11 and 13 are inwardly projecting circular lugs 19 and 20, respectively', the same being eccentrically disposed with respect to the axes of the j bearings 12 and 14 and mounted for rotation on theser eccentrically disposed lugs is a container or housing thatcomprises an annular wall21 and side walls 22 and 23, the latter being removably connected to the annular` wall 21,in any suitable manner.

To minimize the wear between the exter-` A:Fixed on Shaft 16 within ai@ xtemaim-' tor comprising the walls 2l, 22 and 23 is theinn'e rotor of the compressor, the same comprisinga substantially annular block 241 'that-"is providedin its periphery with a plurality of depressions or pockets 25. The

L axes of the circular lugs 19 and 20 are elevated-with respectto the axis of shaft 16 and by virtue of this arrangement and the fact that inner rotor 24 is fixed'directly to said shaft 16. the pocketed periphery of said inner rotor is` positioned immediately adjacent to the. inner periphery of the annular wall 21' of the external rotor at the bottom of the latter, and the space A between the external 'periphery Aof the internal rotor and the inner periphery of the external rotor gradually creases 5 toward the top of the The bearings 12 and 14 are` with a radially disposed passageway 29 that is formed in plate 27, ,and the inner end of each passageway has 'communication with the annular chamber 26 by means ot' a port 30, the latter being formed through theinner portion otplate27. Formed through the im1er-portion` of plate 27 or that-portion which is adjacent to the hub of the inner rotor 24 is a series of ports 31, the same beinlg preferably spaced at equal distances apa and adapted'to communicate as the inner rotor operates with a passageway- 32 that is formed through the eccentric hub 20 and wall 13. Connected to the outer end ot this passageway 32 is a pipe 33 by means of which the air or fluid to be compressed is delivered to the compressor.

The side of rotor 24 that is adjacent to plate 22 is recessed to form an annular chamber 34 and removably positioned on this side of the rotor and closing said chamber is a plate 35. A port 54'1 establishes communication between chamber 34 and champosed and constituting a valve 0r trap, the 4.

operation of which .will be hereinafter more fully described.

Formed in plate 35 are two or more radially disposed overflow ports or passageways l3f(' ,jthe inner ends thereof' communicating with the outer portion of annular'chamljier 34 Jand the outer .ends being extendedJ throughvthe inner portion ot' plate 35 to the outer face thereof. so as to communicate with that portion of annular chamber A 19. (See Fig. 1*.) g

Formed throughthe wall 22 and substan-d tially'in the same horizontal plane with the arcuateports 28 whcnthc same are at their highest point of travel is a passageway and Aformed therein is la valvel seat upon which normally rests a springpressed valve 39, the stem of which' is radially disposed with respect to the axis of the'coinpressor. The spring behind this valve is relatively light so. that when the outer rotor ot the housing comprising the parts 21. 22 and 2?). reaches a certain speed, thev valve will bj.:y centrifugal action be raised from its seat, thereby ,opening the 'passageway 38.

Projecting inwardly 'from annular wall 10 that is immediately below the eccentric lugr between the plates 11 and 22` is an annular so as to occupy the outer' portions of said 65 vflange and operating within the space be l tween this flange and wall or plate 11 isa series ofradially disposed blades 41 that are carried by a hub that is mounted on the hub of the outer rotor and said blades being for the purpose of circulating a cooling medium that fills the space between the outer fixed housing ofthe compressor and the externalafrotor comprising the parts 21, 22 and 23. This cooling medium is delivered to vthe' chamberwithin the outer fixed housing through a pipe 42 that is `tapped into plate 13 and said cooling medium discharges from vthe outer .housing through a pipe 43 that leads downward from the space occupied by the blades 41.

Secured in any suitable manner to the plate v11 of-the housing. ofthefcompressor housing 44 and formed in the outer wall t ereof is a centrally arranged aperture 45 that accommodates the shaft 16. Secured in any. suitablemanner to the outer plate of the housing 44 around the opening- 45 therein is an inwardly projecting collar 46 and carried by the-inner end thereof isy 'a disk 47 Fixed in any suitable manner on the end of bearing 12 that pro-` jects into the chamber within the auxiliary housing44 is a vdisk 48 that has approximately the same diameter and thickness as the disk 47.

Fixed on the shaft 16 between the'disks 47 and 48 is a pair of disks` 49 that are spaced a' slightdistanceapartto form an.

air chamber 50. Radially disposed ports 51 are Jformed in the shaft 16and establish communication bet-ween the chamber 17 in said shaft and the space between disks 49. The diameters of the ,disks 49 .are` slightly greater than the diameters' of the disks land 48, and secured in any suitable manner to' the peripheries ofsaid disks are the inner portions of rings 52 which overlie the' peripheries of the disks 47 and 48 and carried by said rings are ring plates 53, which latter lie-outside of and are spaced apart'from the outer portions o`f disks 47 and 48.

Theinner'peripheries of the ring plates 53 terminate adjacent to the collar 46 and bearing 12, and vby virtue of this construction, the :outer portions of the disks 47'and 48 occupy the narrow annular chambers between the ring plates 53 and outer portions of the ,disks 49, and to prevent the escape of' air frm the chamber'within auxiliary housing 49 through the-spaces between the various plates, and disks, the annular7 c-hambers in which.A ythe peripheral portions of annular chambers.

4outer faceof the outer plate of the auxiliary housing 44 is .a\ ring 54, the' inner portion of'wlnch is spacedtapart from the outer plate 'of'said auxiliary housing, and formed onI the inner face 'of thisring and upon'the .router face of'the outer plate of said' auxiliary housing are flat annular bearing faces 55. Fixed on shaft 16 and positioned in the space between the ring 54 and the adjacent plate of the auxiliary housing is a relatively Secured in any suitablcmanner to thel thin metal fdisk 56, the periphery of which.

is slightly widened to .form a ring 57, and.

the latter being adapted to make, contact with either one of the bearing faces 55.

This 'disk 56-is slightly dished or concavoconvex lso. that when the compressor is at rest, the ring .57 will makecontact with one ofthe bearing faces 55, thereby formingl a seal to preventthe escape of air or liquid from thecompressor.

When the compressor is in operation', the thin met-al disk 56 will by centrifugal forces tend to straighten out or occupy a at direct right angles tothe'axis o the shaft 16, and thus the ring 57 will be'moved plane to and maintain a position midway between the bearing faces55, as illustrated in Figurev 1. Leading from the chamber 'within the auxiliary housing,44 to a suitable container' or storage tank is a compressed fluid' con` veying pipe 58."

The operation of myimproved fluid compresor constructed as heretofore described, is as follows: As shaft 16`is 'driven at a cmpa'ratively High rate of speed, the body of simple or, -l

compound liquid in the eccentric chamber A between y the internal ad external rotors will by centrifugal force be thrown out-I wardly against the inner face of annular '-wall 21 ofthe external rotor so as to form a, substantially annular mobile vor yieldingbody and when a certain speed 'of A,rotation has been reached, the 'external rotor'withthe annular body of 'liquid against the.v inner surface of-wall 21 will rotate with the internal rotor 24, and which' latter is .fixedio shaft' 16. By virtue` of the fact that the in-l ternal rotor is eccentrically disposed/within the external rotor, the periphery of said in= ternal rotor will, during o ration, pass into the annular `lbody of lquld in the chamber A andi as a resul-t, air,igas or, other fluid which 'maybe trapped in said pockets, will 1 be compressed and forced through the vU- shaped traps yor ports 36 into the chamber 34.

As the peripheral portion of the internal the disks 47 and 4 8 operate are partially# rotor travels through the upper portionl of the chamber' A ,the body of liquid will gradually uncover the ports 28 at the outer ends-` illed. with .a vsuitable sealing liquid which,

whenv the compressor, is in operation." l1s thrown outwardly' by a centrifugal force of passageways 29, and as such action .occurs the partial vacuum established in the ockets or recesses as al result of the outwar movement 'of the liquid will cause air,ga's or other fluid to be drawn into the compressor through inlet pipe 33, passageway 32,

y through ports 31, which latter successivelyl A register with the'inner end of passageway 32 and the air from the chamber 26 will pass through the passageways 29 and dischargev A and -forced through the U-shaped passagetank.

ways 36 to chamber 34. l From this chamber the compressed air or other fluid will' discharge through'p'orts 34? into the ,chamber 17 in shaft 16 and from this latter. chainber, the compresseddiuid will pass outwardly through ports 51 to -chamber 50 between the disks 49 and from said chamber, compressed lHuid will p-'ass through outlet pipe 58 to a suitable container or storage 'lhe deXth of the mobile body within chamber will be regulated by the position of the outlet port 38 fforl when the compressor is in o eration, valve-39 will be moved off its set y centrifugal force and any surplusv of liquid within chamber A will pass outwardly through lport 3 8 and will gravitateto the bottom of the chamber within the housing oomprisingthe parts 10, l1, and 13. The U-shaped passageway/s 36 constitute traps orliquid valves to control the discharge of 'the com ressed iiuid from z the pockets 25 and there 1s a certain amount of liquid contained in chamber 34 and in the legs of the U-shaped passagewayls.

When the compressor is in operation, centrifugal force willcause this liquid to 'move' to -the outer portion of the chamber 34 and said liquid will also fill the U-shapedp'assthe erst 1e-g gof which discharges the-coma' pressed air or fluid at a point near the axis of rotation, whereasthe last leg opens into.

priately open and close the inner end of .theA

overflow .discharge passage 5 37 from the pocket and which is located relativelyclose t'o the axis of rotation. By referring to I Figure 1 -it will be seen that-the inner end of the discharge conduit 37 above'the shaft 16 is closed bythe hub- 19, whereas the inner end of the discharge conduit 374 at the lower portion of the` in'ternal rotor and below shaft 16 is open, the same having passed in its revolutionl beyond `the closing zone of the hub 19 and bushing 19, theeccentrical relationof these parts'being such that the inner ends of ports 37 Istart to open when reaehihg or approaching the lower half of the revolution and are fully closed' when reaching or approaching the upper half of the revolution, they remainingopen or partially open during the lower half ofthe revolutionv and being nearly closed during the upper half of the'r'evolution. This prevents back pressure in the chamber in. which Y the internal rotor operates {from exercising a back lash in the discharge conduits from the pockets when said pockets are receiving a fresh supp'ly of iluid, or air (at atmos-- pheric pressure) to .becompressed It will be further noted that the inlet ports 28 enter the outerportions ofthe pockets and above ,the bottoms thereof so that these inner ports are sealed -by the outer ring of liquid before the inal compression of fluid vin the pockets.

. During the operation ofthe compressor, any heatdeveloped as a result of the high speed attained .by the rotors and the action nated by the cdoling -medium thatenters ageways 36. As the -fluid trapped .in the the fixed housing of the compressor through pockets is compressed to the highest .degree at the bottom' or vlower portionv 'ofthe compressor, said fluid will passl through the liquid traps into the annular chamber 34 and in so doing the liquid therein will be displacedfand'the compressed air will finally pass through the ports 34a into the chamber 17 withinv the shaft16. Should an. excess of liquid accumulate in these U-shaped passageways and chamber 34, such excess will find exit through the pass'ageways 37 and discharge therefrom into the chamber A between the internal and external rotors.

'The U-shaped passageway 36 -formed in the internal rotor when combined with the chamber- 34 forms in cross section a substantially reversed N-shaped conduit,

narrow chambers in which the disks 47 andn 48 are positioned, 4cooperate to provide an 11o A of compressingfthe fluid will be dissemi- 'f effective seal to prevent the escape of fluid y pressure past the journal bearing 12.

During the operation of the compressor the sealing liquid will be maintained in annular form 'in the outer portions of the chambers .between the disks 49 and the ring plates 53, thus wholly covering the periph-v eral portions of disks 47 and 48, and as a result, this, com ressed fluid assing into the chamber enc osed by auxiliary housing 44 will be prevented from 'escaping from said chamber and all of said compressed fluid will discharge through outlet 58.

When the compressor is stopped, the sealy tiringl liquid Will by gravity pass to the lower portions of the chambers occupied by t-he disks 47 and 48, and the pressure within 4housing 44 will then pass outwardly through t ring 46 and its action against the disk 56 will force the ring 57 on the edge of said vdisk against. the/outerl one of the seats', thereby maintaining the pressure that hasbeen built up in the compressor.

When the compressor is again started, centrifugal force will cause the disk 56 to move into'a straight radial plane 4with'the peripheral ring 57 out of engagementwith the seats 55. y

In Figure 9'I have illustrated a modified form of ,the liquidse'aled fluid outlet valve 36, this modified construction involving a substantially. U-shaped passageway59, one' 'leg of which 'is connected to the adjacent pocket of the internal rotor andthe outer '25 end of theopposite leg of said passageway communicating with al short arcuate port.

60 which communicates .with the chamber 34 within the -internal rotor. This liquid sealed outlet valve is radially disposed with respect to the axis ofthe internal rotor and lies substantially parallel' with its sidefaces, whereas inthe construction previously described, the liquid sealed valves or outlet ports 36 are disposed transversely of said internal rotor. 1

In Figure'lO I have. illustrated a modified construction wherein a vweighted springpressed valve is utilized for normally .closing the iuid outlet ports from the pockets 25.

In this construction, an outlet portin pas? l sageway 61 is formed through the periphery of the internal rotor andthe lower end of this portis provided with va seat which is normally closed by a valve 62. This valve is carried onthe end of a short lever or arm 63 ,that is fulcrumed on a-bracket 64, the latter being disposed within the chamber 34 in the internal rotor and the free end of thel arm or lever 63 carrying an adjustable weight 65.l

Mountedon the fulcrumof this leveri'is'a spring 66 which tends to normally maintain the valve 62 upon its seat. l When. the internal rotor reaches a certain speed, centrifugal forces will move weight 65 toward theperipheryof the internalrotor, thereby swingingthe arm or lever 63 upon its fulcrum, and consequently unseating -valve 62'to permit .the dischargeof compressed Huid to pass through outlet 61. vIn Figure 111 have-illustrated a modified form of control for the overliow of liquid from the lchamber A through the outlet pas- 'sa'geways 37, said modified construct-ion comprising `the fulcrumed lever 67 the `same carrying ai valve 68 that is adapted to close the 'overflow pa sagewayf? and the vfree end 'of said lever ca rying a float 69 which, when the liquid *reaches a certain height or volume will move the float outwardly, thereby closmg valve 68. f vl In Figures', 7 and 8 I have illustrated a modifiedV construction of the compressor tor is provided on one of its side faces with a disk 70, the periphery of Whiclifis provided with teeth 71 that are adapted to.v engage with teeth 72that are formed on the inner periphery of a ring 73, and the latter being fixed to 'the inner face of one of .the side y plates of the external rotor. The disk 70 rotates with the shaft 16 and the internal rotor carried thereby, and consequently transmits rotary motion-tothe external rotor. In this construction, the bushings x15 which -constitut bearings for the shaft l6`extend outwardly into suitable oil pockets 74 that are formed in the bearings on theside plates of the outer housing, and formed in the in` 11er or bearing faces of these bushings' are longitudinally .disposed oil. ducts 75'. The' tops of 4these bushings are cut away'as designated by 76 and whicl cut-away Aportions communicate with thel ducts 75, and loosely' arranged upon the shaft 16 and positioned in these cut-aw`ay portions 76 are rings 77 which' depend into the adjacent oil pockets 74. Thus as the shaft 16 rotates, oil is car- --riedupvvardly by 'therings 77 and this .oil -will be distributedonto the through the oil ducts 7 5.

For th'e purpose of lubricating'the bearings forjthe external rotor on 'theeccentrically disposed lugs 19 and20, an annular oil pocket such as'7 8 is formed in the inner face of the sidewall of the'outer housing, around the eccentrically disposed lug thereupon, and lextending into this pocket from the adjacent hub on the external rotor is an annular flange 79 upon which is'v loosely mounted a y v v.

'ring 80, and which latter it rotates will .carry oil froin' the lower portion o f the pocket 78 to the upper portion thereof. The

adjacentbushing such as. 19 is -provided with a series of radially. vdisposed oil ducts' 81, the sameA communicating with'longitudinally' disposed ducts such as 82 whichV lead backto the adjacent. pocket" 78.' .8

v (See Fig.:

Yshaft bearings In Figure 13 I have illustrated a construcf tion wherein the, heatl developed during the,

lau

vanes which, when the compressor is in operation, are effective in drawing air into theouter fixed housing, and the latter being provided with suitably located openings such as 84 to permit thecirculation of cooly other fluids can be very easily and quickly lcompressedatov relatively high degrees of. 'pressure f It will be readily understood that minor changes in the size, form and construction of the various parts of my improved fluid 'compressor can be made and substituted for those herein shown and\ described, without 'departing'from the spirit of my invention,

the scope ofV which is set forth in theiap-A pended claims.

I claim:l 1. In a fluid compressor, an external rotor and an internal rotor, the latterv 'comprising a body portion and two head lportions secured inl position at the sides thereof, said head portions being formed with inlet and discharge ducts,'and said body portion being formed witha continuation of said discharge ductl 2.A compressor i of the type described vcomprising the combination` of an external rotor, an internal rotor enclosed thereby and provided with perpherial pockets fhaving reversed N-shaped liquid sealed overflow passages leading into the chamber'ofythe external rotor, and a centrifugallyoperated valve carriedby` the external rotor for-controlling a discharge 4conduit from said chamber.

3. -A compressor of the type described comprising the combination of an external rotor, an internal rotor enclosed thereby and provided .with peripheral pockets having reversed N-shaped liquid sealed overflow ,passages leading into the chamber of the external rotor, and a centrifugally operated valve carried by the external rotor for controlling a discharge conduit from'said chamber, there being a'radially 'disposed spring for opposing said centrifugally 'operated yalve.

- 4. The combination of a stationary housing, an external rotor arranged therein an internal rotor, aseries'of blades vcarried by said external rotor, and an annular flange carried by the stationary housing and extending between the external rotor and said blades,` said flange forming a collecting chamber,and a7 discharge pipe leading fromv -4 said chamber.

5. The combination of a stationary housingjhaving .an inletvand an outlet for a cooling liquid, a rotor, blades carried by said rotor, and an annular flange in said housing between said blades and said rotor, said flange being also located between the inlet` and outlet openings for the cooling liquid.

G. In a fluid compressor, the combination of an internal rotor, an external rotor wholly enclosing and sealing vsaid internal rotor, a/casing completely enclosing said external rotor,` a hollow shaft journaled in said casing and supporting said internal rotor, said external rotor being jprovided with suitable liquid and said internal rotor havingperipheral'pockets'adapted to be sealed vby said liquid whereby'the fluid trapped in said pockets is compressed by said liqcuid and forced therefrom', said internal rotor being provided with an intake'chamber closed to the atmosphere, an inletconnection leading through said casing into said intake chamber, inlet ducts leading from said chamber and opening into each of, said pockets at the highest point thereof centripetally disposed outlet ducts formed in said internkal'rotor and leading from the bottom of each pocket to said ressure chamber,

communicating openings ormed radially in said internal Irotor and said shaft and connecting the pressure chamber of said internal rotor with said hollow shaft, and discharge connections communicating with said hollow haft for conveying away thetcompressed 7. In a Quid compressor, the combination f of a' housing, alhollow ported shaft journaled therein,.an external rotor, an internal rotor fixed on said shaft and jonrnaled on bosses formed on said housing, said shaft and said internal rotor being eccentris lcally disposed relative to saidhousing and to said external rotor, a mobile body'in said external'rotor, said internal rotor being pro- .vided in it's periphery with pockets in which thefluid is trapped and compressed by said mobile body, discharge ducts leading from the bottom of each pocket into a pressurechamber formed in said internal rotor, com` municating .ports formed in saidv internal rotor and said shaft for conveying the compressed fluid from said pressure chamber to said shaft, a casing secured to said housing and having a pressure chamber in commun1 cation with said hollow shaft, a dijcharge connection leading from said? pressure cham ber, means for providing a liquid 'seal ,bctween the atmos here and said chamber during t e operationof t e com-l pressor, and a flexible late, operable by the- Y pressure in said cham er for sealing said chamber to the atmosphere when the -compressor is idle. ru

8. In a fluid compressor, the combination with a housing, a mobile body' thercim'a' shaft eccentrically journaled relative to said housing, an internal rotor fixed' on said shaft,

an external rotor loosely arranged within said housing and completely'enclosing said internal rotor, said housing completely enclosing said external rotor, said internal .rotor being provided in its periphery with pockets in which-thel fluid is trapped and compressed by said mobile body, inlet ducts iorined in said internal rotor and opening into each pocket at the highest point thereof, liquid seal discharge ductsl formed in said internal rotor leading from the bottom of 1" into said discharge connection. an inlet connection leading into said housing, and an outlet connection leading from 4said housing for circulating therethrough a cooling medium.

9. A- compressor comprising an outer rotor arranged to contain a liquid, an inner rotor Within the outer rotor arranged to receive rotative impetus romthe liquid Within the outer rotor when the `outer rotor is rotated, wells in the periphery of the Ainner rotor', passages through the inner rotor for conducting -air into the space between the' rotors, passages through the inner rotor from said Wells forl conducting au' from said wells,

and means for maintaining a liquid seal at the outer side of the inner rotor for theouter ends of said lasty named passages. -4 i In testimony' whereof I hereunto aiix my signature this 6th day of February, 1920. 4

` JOHN O. CARREY. 

